The present inventions are generally directed to the use of five process color toners, and developer compositions thereof, and more specifically, the present invention is directed to developer and toner compositions with certain pigments, or mixtures thereof, wherein full color and HiFi, where true process colors are selected, developed images with excellent resolution can be obtained, and wherein high quality pigment dispersions are generated by flushing the pigments or by the use of dispersing agents during processing. In embodiments, the toners of the present invention contain flushed pigments, and wherein there is selected a wet pigment, or wet cake for each colored toner followed by heating to melt the resin or render it molten and thereafter shearing, and wherein water is removed or substantially removed from the pigment and there is generated in embodiments a polymer phase around the pigment enabling, for example, substantial, partial passivation of the pigment. A solvent can be added to the product obtained to provide a high quality dispersion of pigment and resin, and wherein the pigment is present in an amount of from about 25 to about 50, and preferably from about 30 to about 40 weight percent. Subsequently, the product obtained is mixed with a toner resin, which resin can be similar, or dissimilar than the resin mixed with the wet pigment, to provide a toner comprised of resin and pigment, and wherein in embodiments the pigment is present in an amount of from about 2 to about 20, and preferably from about 2 to about 15 weight percent based on the weight of the toner components of resin and pigment. In embodiments, there is formed one toner with five different pigments, or five toners with different pigments. There is provided in accordance with the present invention five colored toners with the colored pigment dispersed to a high quality state. The quality of the pigment dispersion as measured by Projection Efficiency is preferably between 70 percent and 98 percent as indicated herein. With the present invention, there is enabled a combination of toners with a large color gamut, especially in reflection developed images and with transparencies, and wherein with transparencies a substantial amount of scattered light, and embodiments most of the scattered light is eliminated allowing, for example, about 70 to about 98 percent (high quality pigment dispersion) of the transmitted light passing through a fused image on a transparency to reach the screen from an overhead projector. The toner and developer compositions of the present invention can be selected for electrophotographic, especially known xerographic imaging and printing processes, and more especially, full color processes.
Of importance with respect to the present invention in embodiments are the economical and environmentally friendly pigments, or mixtures of pigments selected for each toner, and the combination set, or gamut of toners, such as the cyan toner, the magenta toner, the orange or red toner, the yellow toner, and the black toner, as it is with these pigments that there is enabled the advantages of the present invention illustrated herein and including excellent stable triboelectric characteristics, acceptable stable admix properties, superior color resolution, the capability of obtaining any colors desired, that is a full color gamut, for example thousands of different colors and different developed color images, substantial toner insensitivity to relative humidity, toners that are not substantially adversely affected by environmental changes of temperature, humidity, and the like, the provision of separate toners, such as black, cyan, magenta, orange or red, and yellow toners, and mixtures thereof with the advantages illustrated herein, and which toners can be selected for the multicolor development of electrostatic images. The specific selection of colored toners together with having the pigments exceptionally well and substantially dispersed, and the image fused so that the image surface is smooth enables a large color gamut which assures that thousands of colors can be produced. The toner compositions of the present invention usually contain surface additives and may also contain charge additives, waxes, such as polypropylene, polyhydroxy compounds, such as the UNILINS.RTM. available from Petrolite Chemicals.
In embodiments of the present invention there are provided HiFi color processes wherein the color gamut refers to a range of colors that an imaging system can generate. One way of quantifying the color gamut is in terms of the number of pantone colors that the imaging device can produce. For example, there are about 1,000 standard pantone colors used in the graphic arts and about half of them can be produced by a typical four-color printing process, however, the remainder are outside of its color gamut. The specific HiFi toners and methods of the present invention in embodiments thereof involve the use of one or more additional process colors, such as orange or red, in addition to the usual cyan, magenta, yellow and black process colors. In HiFi color, the additional colors used are true process colors. In the image processing stage, the image is screened into the process color separations which are printed over each other. All possible mixtures (overprints) of the process colors can exist in the image. Thus, this method can produce all of the image colors that are between the 4-color gamut and the additional process color, such as orange. In contrast, in graphics arts pantone colors are traditionally printed by highlight color methods (four process colors plus a spot color). This requires hundreds of spot color inks. When pantone colors by the HiFi color method are generated in accordance with embodiments of the present invention, each additional process color, preferably orange, can produce many pantone colors by combinations with the other process colors. Thus, a single HiFi process color, such as red or orange, can generate up to 70 additional pantone colors.
Combination or set refers, in embodiments of the present invention, to separate toners that are not mixed together, rather each toner exists as a separate composition and each toner is incorporated into separate housings containing carrier in a xerographic machine, such as the Xerox Corporation 5775. For example, the cyan toner is present in one developer housing, the magenta toner is present in a second separate developer housing, the yellow toner is present in a third separate developer housing, the black toner is present in a fourth separate developer housing, and the orange or red toner is present in a fifth separate developer housing; and wherein each developer housing includes therein carrier particles such as those particles comprised of a core with a coating thereover.
Certain toner and developer compositions are known, including toners with specific pigments, such as magenta pigments like 2,9-dimethyl-substituted quinacridone and anthraquinone dye identified in the Color Index as Cl 60710, Cl Dispersed Red 15, diazo dye identified in the Color Index as Cl 26050, Cl Solvent Red 19; cyan pigments such as copper tetra-4-(octadecyl sulfonamido) phthalocyanine, X-copper phthalocyanine pigment listed in the Color Index as Cl 74160, Cl Pigment Blue, and Anthrathrene Blue, identified in the Color Index as Cl 69810, Special Blue X-2137; yellow pigments such as diarylide yellow 3,3-dichlorobenzidene acetoacetanilides, a monoazo pigment identified in the Color Index as Cl 12700, Cl Solvent Yellow 16, a nitrophenyl amine sulfonamide identified in the Color Index as Foron Yellow SE/GLN, Cl Dispersed Yellow 33, 2,5-dimethoxy-4-sulfonanilide phenylazo-4'-chloro-2,5-dimethoxy acetoacetanilide, and Permanent Yellow FGL; and black pigments such as REGAL 330.RTM. carbon black. Moreover, toners with certain colored pigments are illustrated in U.S. Pat. No. 5,262,264, the disclosure of which is totally incorporated herein by reference.
Developer compositions with charge enhancing additives, which impart a positive charge to the toner resin, are also known. Thus, for example, there is described in U.S. Pat. No. 3,893,935 the use of quaternary ammonium salts as charge control agents for electrostatic toner compositions; U.S. Pat. No. 4,221,856 discloses electrophotographic toners containing resin compatible quaternary ammonium compounds in which at least two R radicals are hydrocarbons having from 8 to about 22 carbon atoms, and each other R is a hydrogen or hydrocarbon radical with from 1 to about 8 carbon atoms, and A is an anion, for example sulfate, sulfonate, nitrate, borate, chlorate, and the halogens such as iodide, chloride and bromide; and similar teachings are presented in U.S. Pat. No. 4,291,112 wherein A is an anion including, for example, sulfate, sulfonate, nitrate, borate, chlorate, and the halogens. There are also described in U.S. Pat. No. 2,986,521 reversal developer compositions comprised of toner resin particles coated with finely divided colloidal silica. According to the disclosure of this patent, the development of electrostatic latent images on negatively charged surfaces is accomplished by applying a developer composition having a positively charged triboelectric relationship with respect to the colloidal silica.
Further, there are disclosed in U.S. Pat. No. 4,338,390, the disclosure of which is totally incorporated herein by reference, developer compositions containing as charge enhancing additives organic sulfate and sulfonates, which additives can impart a positive charge to the toner composition. Moreover, there are disclosed in U.S. Pat. No. 4,298,672, the disclosure of which is totally incorporated herein by reference, positively charged toner compositions with resin particles and pigment particles, and as charge enhancing additives alkyl pyridinium compounds. Additionally, other patents disclosing positively charged toner compositions with charge control additives include U.S. Pat. Nos. 3,944,493; 4,007,293; 4,079,014; 4,394,430 and 4,560,635, which illustrates a toner with a distearyl dimethyl ammonium methyl sulfate charge additive.
Moreover, toner compositions with negative charge enhancing additives are known, reference for example U.S. Pat. Nos. 4,411,974 and 4,206,064, the disclosures of which are totally incorporated herein by reference. The '974 patent discloses negatively charged toner compositions comprised of resin particles, pigment particles, and as a charge enhancing additive ortho-halo phenyl carboxylic acids. Similarly, there are disclosed in the '064 patent toner compositions with chromium, cobalt, and nickel complexes of salicylic acid as negative charge enhancing additives.
There is illustrated in U.S. Pat. No. 4,404,271 a complex system for developing electrostatic images with a toner which contains a metal complex represented by the formula in column 2, for example, and wherein ME can be chromium, cobalt or iron. Additionally, other patents disclosing various metal containing azo dyestuff structures wherein the metal is chromium or cobalt include 2,891,939; 2,871,233; 2,891,938; 2,933,489; 4,053,462 and 4,314,937. Also, in U.S. Pat. No. 4,433,040, the disclosure of which is totally incorporated herein by reference, there are illustrated toner compositions with chromium and cobalt complexes of azo dyes as negative charge enhancing additives. Further, of interest are U.S. Pat. Nos. 5,262,264 and 5,437,949, the disclosures of which are totally incorporated herein by reference.